Search Results (604)

Cold-mercury gilding uses mercury as an adhesive to bond gold foil onto the surface of copper and silver artifacts. This technique and mercury gilding (fire gilding) both belong to the Au-Hg system and are closely related in technology. Clarifying the technical differences between them is of great significance for revealing the developmental sequence of ancient gilding technologies. On the basis of reconstructing traditional fire gilding, simulated cold-mercury-gilded samples were successfully prepared using experimental archeological methods, and multi-scale characterization was performed using SEM-EDS, XRD, and XPS. The results show that the surface of cold-mercury-gilded samples displays a micromorphology of folded and overlapped gold foil accompanied by locally dense particle aggregation. The cross-section of the gold layer exhibits a multilayer stacked structure, in which mercury is enriched at the gold layer/substrate interface and forms an AuHgCu/Ag diffusion layer. Room-temperature-stable Au-Hg and Ag-Hg phases such as Au₂Hg and AgHg are present in the gold layer, reflecting complex phase transformation behavior of the Au-Hg/Ag-Hg system at room temperature. During cold-mercury gilding, liquid mercury first adheres to the gold foil, and then interdiffusion and phase reactions occur between mercury, gold, and copper/silver atoms at room temperature. Intermetallic compounds and diffusion layers formed at the interface achieve firm bonding between the gold layer and the substrate. Both cold-mercury gilding and mercury gilding achieve metallurgical bonding through atomic interdiffusion. However, affected by differences in the initial state of mercury and operating temperature, the phase transformation and atomic diffusion behaviors of the system differ significantly, which are ultimately reflected in the cross-sectional structure of the gold layer, the composition of the interfacial diffusion layer, and the types of phases. Therefore, mercury-gilded artifacts show superior gold layer durability and bonding strength with the substrate compared with cold-mercury-gilded artifacts. Both techniques pioneered the application of mercury in metallic gilding and represent important innovations in ancient surface decoration technology. Full article

Defect engineering and metal–support coupling provide an effective route to tune interfacial charge dynamics for selective photocatalytic CO₂ reduction. Here, Ti-vacancy-rich Bi₄Ti₃O₁₂ (BTvO) nanosheets were prepared and decorated with Au nanoparticles (Au NPs) to build Au-BTvO junctions that favor multi-electron/proton transfer toward deep hydrogenation. The optimized 3%Au-BTvO achieved high hydrocarbon productivity under visible light (λ > 420 nm), delivering CH₄ and C₂H₆ formation rates of 92.66 and 17.96 μmol g⁻¹ h⁻¹, respectively, with stable performance over 25 h. Spectroscopic analyses reveal higher CO₂ uptake and more effective surface activation, increased water adsorption with a more favorable interfacial hydration environment, and time-dependent formation of key C₁ and C₂ intermediates. In situ light-irradiation XPS, PL mapping, and KPFM collectively demonstrate directional electron transfer from Bi₄Ti₃O₁₂ to Au and amplified surface band bending, enabling efficient charge separation and accelerated surface reduction. This work highlights defect–metal synergy as a general strategy to boost activity, selectivity, and durability in visible-light CO₂-to-methane conversion. Full article

Herein, an electrochemical sensor is reported for the first time based on an ordered macro–microporous composite derived from metal–organic frameworks (MOFs) for the highly sensitive detection of auramine O (AO), a Group 2B carcinogen. The hierarchical pore architecture, integrating an ordered macroporous network with a microporous ZIF-8 framework, enables the uniform dispersion of a high density of catalytically active sites. The interconnected macroporous channels facilitate efficient mass transport and rapid removal of reaction byproducts, effectively preventing pore blockage and ensuring stable sensing performance during repeated measurements. Owing to these structural advantages, the proposed sensor exhibits outstanding analytical performance toward AO detection, with a sensitivity of 0.4843 μA μM⁻¹, a detection limit of 0.168 μM (S/N = 3), and a wide linear range from 0.5 to 50 μM. Moreover, the sensor demonstrates excellent selectivity and reproducibility, maintaining reliable responses even in the presence of 100-fold excess common food constituents such as tartrazine and glucose. Real sample analysis further confirms its high accuracy and operational stability. Overall, the electrochemical sensor based on silver nanoparticle-decorated ordered macro–microporous ZIF-8 synthesized via in situ reduction shows great potential as a portable and on-site tool for rapid AO detection in food. More broadly, ordered macro–microporous MOF-derived materials represent a promising platform for advanced electrochemical sensor applications. Full article

Achieving natural esthetics has become essential for successful dental restorations and supports the use of modern non-metal materials. However, complexity in esthetic features of natural teeth, determined by both inherent color factors and hierarchical and gradient microstructures, makes recording, determination, and reproduction difficult. This often leads to misunderstanding during manufacturing and dissatisfaction with the final outcome, even when using advanced digital tools. The aim of this study was to investigate a new, easy-to-handle digital tool for determining the color of restorative materials. An industrial-level handheld color identifier, the NCS Colourpin SE, together with the corresponding NCS color system, was tested on three materials: dental resin nanocomposite, self-glazed zirconia (SGZ), and Decore zirconia pellets. The repeatability and impacts of geometrical contributions such as surface roughness and thickness on different colors were measured. The Colourpin SE offered promising repeatability. Decore zirconia showed more than 90% repeatability for most of the colors, independent of thickness. The NCS scanner showed slightly better repeatability than earlier in clinical trials with an intraoral scanner. The shades A3.5 and A3 had lower repeatability, varying from 50 to 90%. It identified effects of material thickness and surface roughness, where the thicker samples were identified with higher blackness levels, and surface roughness seemed to be coupled with a lower blackness level in color identification codes. Small but consistent differences between materials were detected, suggesting that material and manufacturing methods affect the final shade. The NCS Colourpin SE shows potential to be developed into an affordable and easy-to-handle scanner for the identification of a patient’s tooth color, enabling synchronization with digital workflows and improving the match between restoration and the patient’s natural teeth. Nevertheless, further research and development in customized applications for color identification in esthetic dentistry is still required through multidisciplinary collaboration. Full article

Wind-induced roof-lifting accidents occur frequently in metal roofs, making the monitoring of wind uplift resistance an important part of building health monitoring. This paper proposes an integrated monitoring and reinforcement method for metal roofs using embedded fiber Bragg grating (FBG) smart rebars, develops smart rebars with both sensing and load-bearing functions, and conducts wind uplift tests in accordance with relevant standards. The experimental results show that: 1. The smart rebar can achieve high-frequency real-time monitoring at 100 Hz, accurately capture the dynamic force characteristics of the roof panel throughout the wind load application process, and precisely locate the damaged area. 2. The smart rebar and the roof panel form an integrally stressed “rebar–panel” system. Under wind load, they deform coordinately; the smart rebar uniformly transfers the load from local high-stress areas to the entire roof system, optimizing the force transmission path and avoiding premature damage caused by local stress exceeding the limit. During the experiment, it effectively restricts the deformation of the decorative panel and prevents secondary damage caused by “splashing”. 3. Based on the experimentally measured strain data and the degree of roof damage, a graded-control index system is established with a “first-level alarm threshold of 1800 με, second-level alarm threshold of 2400 με, and third-level alarm threshold of 3000 με”. Each level of alarm corresponds to relevant disposal measures, realizing closed-loop management from data monitoring to risk response. The smart rebar system serves both load-bearing and sensing functions, fulfilling the practical engineering needs of monitoring and enhancing the roof, thereby achieving the dual purposes of monitoring and reinforcement. Full article

The green synthesis of nanomaterials using biological resources has emerged as a sustainable alternative to conventional chemical routes. In this study, the wild ectomycorrhizal mushroom Russula sanguinea (Rs) was employed as a natural reducing and stabilizing agent for the biosynthesis of silver-decorated zinc-based nanostructures (Ag–ZnNSs/Rs). The formation and physicochemical properties of the nanostructures were systematically characterized using UV–Vis spectroscopy, FT-IR spectroscopy, SEM, TEM, and EDX analysis. Transmission electron microscopy revealed predominantly spherical nanoparticles with good dispersion, and quantitative analysis of 227 individual particles demonstrated an average diameter of 19.36 ± 7.89 nm (range: 10.92–61.00 nm). FT-IR analysis confirmed the involvement of fungal biomolecules in metal ion reduction and surface stabilization, indicating effective bio-capping of the nanostructures. The biofunctional performance of the biosynthesized Ag–ZnNSs/Rs was evaluated through antioxidant and antimicrobial assays. Compared to the crude mushroom extract, the nanostructures exhibited significantly enhanced 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with an IC₅₀ value of 7.29 ± 0.10 mg mL⁻¹ compared to 13.66 ± 0.15 mg mL⁻¹ for the crude extract. In addition, notable antimicrobial activity was observed against representative Gram-positive and Gram-negative bacteria (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) as well as the yeast Candida albicans. Overall, this study demonstrates that Russula sanguinea is an effective biological platform for the green synthesis of silver-decorated zinc-based nanostructures with improved biofunctional properties, highlighting the potential of wild mushrooms as underexplored resources in sustainable nanomaterial development. Full article

Bioresorbable scaffolds (BRS; also referred to as bioresorbable vascular scaffolds, BVS) represent a promising approach in interventional cardiology, offering theoretical advantages such as temporary mechanical support followed by complete resorption. However, clinical experience has revealed challenges, including late-stage scaffold thrombosis and heterogeneous scaffold discontinuity during degradation, prompting investigation into host immune responses. Neutrophil extracellular traps (NETs), which are network-like structures composed of decondensed chromatin decorated with antimicrobial proteins, have emerged as critical mediators of vascular inflammation and thrombosis. This review explores the intersection between NET biology and BRS performance, investigating how NETosis affects biocompatibility, degradation kinetics, and device-related complications. We discuss the molecular mechanisms that trigger neutrophil activation and NET formation in scaffold materials, the effect of NET components on polymeric and metallic scaffold degradation, and emerging biomarkers to monitor NET-mediated complications. We also evaluate therapeutic strategies targeting NET pathways, including DNase-based therapies, peptidylarginine deiminase 4 (PAD4) inhibitors, and anti-inflammatory coatings that can optimize next-generation BRS outcomes. Understanding the immunological environment surrounding bioresorbable vascular devices is crucial for developing scaffolds that deliver predictable degradation while minimizing adverse inflammatory responses. Full article

Lightweight, efficient, and reversible hydrogen storage materials are critical for the advancement of hydrogen-based energy technologies. In this work, we present a comprehensive density functional theory (DFT) investigation of hydrogen storage in pristine and metal-decorated C₈ carbon quantum dots (CQDs), representing ultrasmall, highly curved nanomaterials at the molecular–nanoscale interface. Lithium, magnesium, and titanium were investigated as representative decorating metals to tailor hydrogen adsorption strength and reversibility. The pristine C₈ quantum dot is structurally stable but exhibits negligible hydrogen affinity (−0.062 eV per H₂), rendering it unsuitable for practical storage applications. In contrast, metal decoration significantly enhances hydrogen adsorption while preserving molecular H₂ physisorption, yielding optimal single-molecule adsorption energies of −0.172, −0.304, and −0.451 eV for Li-, Mg-, and Ti-CQDs, respectively. Sequential adsorption analysis indicates exceptionally high hydrogen uptakes of up to 18 H₂ molecules for Li-CQD and 20 H₂ molecules for both Mg- and Ti-CQDs, corresponding to very high theoretical gravimetric capacities. Energy decomposition and interaction region analyses demonstrate that hydrogen uptake proceeds via a cooperative physisorption mechanism driven by dispersion, electrostatic, and polarization interactions, strongly enhanced by quantum confinement and extreme curvature effects inherent to the CQD. Grand canonical thermodynamic modeling confirms fully reversible hydrogen storage under practical temperature and pressure conditions. Among the systems studied, Mg-CQD exhibits the most favorable balance between adsorption strength and desorption accessibility, delivering a remarkable reversible gravimetric hydrogen storage capacity of 21.7 wt%, significantly surpassing most metal-decorated graphene-, fullerene-, and carbon nanotube-based materials reported to date. These results establish metal-decorated C₈ quantum dots as a new class of high-performance nanomaterials for reversible hydrogen storage and demonstrate the potential of ultrasmall carbon quantum dots to overcome the long-standing trade-off between hydrogen uptake and reversibility in nanostructured storage media. Full article

Phosphate coatings were obtained by cold method from solutions based on Mazev Salt (containing Mn(H₂PO₄)₂∙2H₂O and iron phosphates). Metal nitrates and nitrites were introduced into solutions as accelerators of the phosphating process. To obtain green and blue phosphate coatings, procyon olive green and methylene blue dyes (8 g/L) were added into the solutions. Colored phosphate coatings are deposited unevenly on the steel surface. The thickness of the modified phosphate films was estimated from SEM images of the cross-section samples and determined to be 3–4 microns. Colored phosphate coatings are fine-grained with a grain size of 170–190 nm, which was determined using an atomic force microscope. Phosphate films continue to exhibit protective properties when heated to 100 °C. With a further increase in temperature, the protective ability of the film is significantly reduced. Colored phosphate films have a low coefficient of friction (0.1–0.15). The breakdown voltage of colored phosphate coatings is 180–200 V, which characterizes low electrical insulation ability. Based on the established properties, colored phosphate coatings can be used as protective and decorative. Full article

This paper provides a systematic review of urushiol-based antibacterial coatings for lacquer art applications, focusing on three key dimensions: molecular mechanisms, durability, and safety. Natural lacquer films form a dense three-dimensional network through laccase-catalyzed oxidative cross-linking, endowing them with excellent mechanical properties and corrosion resistance, while the catechol structure in urushiol confers broad-spectrum antibacterial potential. The article elaborates on the synergistic antibacterial mechanisms of urushiol, including covalent reactions with bacterial proteins via quinone intermediates, induction of oxidative stress, and metal ion chelation. It also reveals the dynamic change pattern of coating antibacterial activity over time, characterized by “high initial efficiency- gradual mid-term decline—long-term stabilization,” a process influenced collectively by side-chain unsaturation, degree of curing, and environmental factors such as temperature, humidity, and light exposure. From an application perspective, this review examines modification approaches such as silver/titanium dioxide composite systems, structurally regulated sustained-release strategies, and anti-adhesion surface designs, while pointing out current limitations in artistic compatibility, long-term durability, and safety assessment. Particularly in scenarios involving food contact and cultural heritage preservation, migration risks from unreacted urushiol monomers and metal nanoparticles, as well as the inherent sensitization potential of urushiol, remain critical challenges for safe application. Accordingly, this paper proposes the establishment of a holistic research framework covering “material design–process control–performance evaluation” and advocates for the development of functional coating systems with low migration, high biocompatibility, and preserved aesthetic value. Such advances are essential to promote the sustainable development and safe application of urushiol-based antibacterial coatings in fields such as cultural heritage conservation, daily-use utensils, and high-end decorative arts. Full article

In this study, novel Mo-decorated core–shell zeolite composites, namely ZSM-5@SAPO-34 and SAPO-34@ZSM-5, were synthesized and evaluated as catalysts for methane dehydroaromatization (MDA). Core–shell structures were effectively fabricated via sequential hydrothermal synthesis, utilizing SAPO-34 and ZSM-5 as cores, which were subsequently subjected to hydrothermal growth in ZSM-5 and SAPO-34 reacting solution, respectively. Catalysts with varying SAPO-34/ZSM-5 mass ratios and Mo loadings were thoroughly characterized by the XRD, BET, SEM-EDS, and NH₃-TPD techniques. The catalytic performance in the MDA reaction revealed a strong correlation between composite architecture, acidity, Mo dispersion, and product selectivity. Introducing H⁺SAPO-34 into both core–shell composites enhanced ethylene-to-benzene conversion due to the acidic confinement provided by SAPO-34. In contrast, non-protonated SAPO-34@ZSM-5 showed limited activity as a result of its weak acidity and inadequate Mo dispersion. Among all catalysts, H⁺ZSM-5@SAPO-34 with a 3:1 core–shell mass ratio delivered the highest benzene yield and stability, outperforming the benchmark, H⁺ZSM-5. This work highlights the potential of tailored core–shell zeolite composites in optimizing acid–metal interactions and improving catalytic performance in hydrocarbon transformations. Full article

Ni removal from waste streams wherein it is present in organically complexed forms remains a major industrial challenge since organically bound Ni does not readily precipitate and is poorly removed by conventional adsorbents. In this work, two effective adsorbents, namely thin-layered porous carbon (TLPC) and MnO₂-decorated TLPC (i.e., MnO₂-TLPC), were developed for the removal of both inorganic and organically complexed Ni(II) from synthetic and real waste streams. Both adsorbents removed inorganic Ni(II) as well as Ni(II) present in organically complexed forms, achieving up to ~80% removal from both real and synthetic electroplating wastewater. Critically, Ni removal efficiencies were maintained over five adsorption–desorption cycles, demonstrating excellent regeneration and reuse potential. The Ni removal by TLPC was pH-dependent, whereas MnO₂-TLPC showed minimal pH sensitivity. TLPC relies on outer-sphere, charge-driven adsorption, whereas MnO₂-TLPC achieves stronger Ni binding through inner-sphere complexation promoted by oxygen- and nitrogen-based functional groups. The sorbents also reduced dissolved organic carbon, with TLPC displaying higher organic removal efficiency. Mechanistic analysis indicates that Ni uptake is primarily governed by sorption of both complexed and inorganic Ni(II) present in equilibrium with the complex, combined with sorption of the free ligand itself. The sorption of the free ligands and inorganic Ni(II) drive Ni–ligand decomplexation in the solution phase, enabling further Ni removal. Overall, TLPC provides a low-cost, high-performance option for treating alkaline wastewaters with elevated Ni and organic loadings, while MnO₂-TLPC offers robust, pH-resilient removal under circumneutral conditions. These findings position both materials as promising candidates for practical wastewater treatment applications targeting complexed metal contaminants. Full article

This study identifies the technological signature of ancient and alternative “Chu” and “Kriab” gold glass mosaic mirrors from Thailand. Although these mirrors play an important role in Thai decorative heritage, their production routes and interfacial chemistry at the lead-to-glass interface have remained unclear. A survey of 154 sites across Thailand shows mosaic glass was widely distributed and likely produced during the Ayutthaya period (~300 years ago). Portable X-Ray Fluorescence (pXRF), Wavelength-Dispersive XRF (WD-XRF), scanning electron microscopy (SEM), and X-ray Photoelectron Spectroscopy (XPS) were used to examine the material properties of observed Chu mirrors. Most samples can be classified as a mixed lead–alkaline glass type, with a PbO content ranging from 4.28 to 48.17 wt%. Their yellow tone is controlled by iron and manganese redox states. Chemical and physical analyses distinguish between Chu from the northern part of Thailand and Kriab from the central part of Thailand, which share a silica source but rely on different fluxes, pointing to different glass workshops. Crucially, XPS depth profiling reveals a well-defined interfacial reaction zone extending to approximately 6 nm in the ancient mirrors, predominantly characterized by disordered, chain-like Pb–O–Pb linkages. These polymeric structures enable a “chemical bridging” mechanism that effectively accommodates interfacial strain arising from thermal expansion mismatch, thereby ensuring exceptional long-term adhesion. Furthermore, the depth-dependent distribution of hydrated lead species and the emergence of photoelectron energy-loss features beyond ~6 nm distinguish the superior metallic integrity of the ancient coatings from the alternative reproductions. This distinct stratification confirms that ancient artisans achieved a sophisticated balance between a chemically bonded interface and a coherent metallic bulk. These findings offer significant insights into the ingenuity of ancient Thai artisans, providing a scientific foundation for the conservation, restoration, and replication of these culturally significant artifacts. Full article

Background/Objectives: Research on noble metal nanoparticles (NPs) has increased over the past three decades, with advancements in synthesis techniques refining their physicochemical characteristics, including size, shape, and surface chemistry. Bimetallic NPs (BNPs) offer synergistic properties contributed by both metals. Gold (Au) and palladium (Pd) NPs possess low toxicity, high biocompatibility and loading, ease of synthesis and surface modification. Doxorubicin (DOX) and 5-fluorouracil (5-FU) are potent chemotherapeutic drugs but are rapidly metabolised in the body, producing severe side effects, limiting their use. Hence, innovative strategies to mitigate this is needed. Methods: In this study, AuPd NPs in a core-shell formation were chemically synthesized. The AuPd NPs were conjugated to 5-FU and DOX-encapsulated CS complexes and decorated with the targeting moiety transferrin (Tf). Results: Transmission electron microscopy and nanoparticle tracking analysis confirmed that the BNPs were spherical, with an average size of 73.4 nm. Functionalized BNPs were able to encapsulate more than 70% of 5-FU and DOX, resulting in a controlled drug release profile at pH 4.2. Cytotoxicity levels in human cancer cells, HeLa (cervical carcinoma) and MCF-7 (breast adenocarcinoma), as well as in non-cancer HEK293 (embryonic kidney) cells, revealed that the Tf-targeted nanocomplexes were HeLa cell-specific, with no significant cytotoxicity in the HEK293 cells. Tf-mediated cellular uptake was confirmed by receptor competition studies in the HeLa cells. Apoptosis and oxidative stress analysis confirmed cell death by apoptosis, consistent with the action of 5-FU and DOX. Conclusions: This study highlighted the potential of this BNP-nanocomplex as a suitable vehicle for drug delivery. Full article

Pharmaceutical residues are increasingly emerging in global drinking water sources, posing serious ecological and public health challenges by altering the physicochemical balance of aquatic systems. Among available purification approaches, adsorption remains one of the most promising techniques due to its simplicity, cost-effectiveness, and efficiency. In this work, a ternary nanocomposite of Cu- and ZnO-decorated carboxylated graphene oxide (Cu/ZnO@CGO) was synthesized and utilized for highly efficient and ultrafast removal of the antidiabetic drug metformin from aqueous environments. The adsorption mechanism arises from a synergistic combination of surface complexation on Cu nanoparticles, cation–π and π–π electron donor–acceptor interactions with the CGO aromatic structure, and hydrogen bonding through the amino groups of metformin and the oxygen-rich functional moieties of ZnO and CGO. The nanocomposite was thoroughly characterized using FTIR, XPS, XRD, SEM, HRTEM, and TGA analyses, confirming its well-defined hybrid structure. Unlike conventional single-phase or binary systems, the Cu/ZnO@CGO nanocomposite demonstrated remarkable cooperative effects that enhanced its performance through the integration of metal–ligand coordination, π–π stacking, cation–π forces, and hydrogen bonding. These interactions contributed to an outstanding adsorption capacity of 232.56 mg·g⁻¹ and an exceptionally fast equilibrium time of only 25 min. Moreover, the material maintained excellent reusability, with merely a 4.1% decline in efficiency after five regeneration cycles, and achieved almost complete removal of metformin (99.7 ± 3.4%) from several real water samples, namely river, tap, and bottled water. The unique structural design of Cu/ZnO@CGO prevents CGO aggregation and facilitates efficient contaminant capture even at trace concentrations, establishing it as a highly competitive and sustainable adsorbent for pharmaceutical wastewater treatment. Overall, this study highlights a novel and rationally engineered nanocomposite whose synergistic surface chemistry bridges adsorption and detoxification, providing valuable insight into the next generation of multifunctional graphene-based materials for environmental remediation. Full article